Endothelin receptor antagonists

ABSTRACT

Novel to isooxazoles, oxazoles, thiazoles, isothiazoles and imidazoles, pharmaceutical compositions containing these compounds and their use as endothelin receptor antagonists are described.

This is a divisional of application Ser. No. 08/750,018 filed Feb. 2,1998 now U.S. Pat. No. 6,030,970; which is a 371 of InternationalApplication No. PCT/US96/12584, filed Aug. 2, 1996; which claims thebenefit of the following provisional applications: Ser. No. 60/001,794,filed Aug. 2, 1995 and Ser. No. 60/011,009, filed Feb. 1, 1996.

FIELD OF INVENTION

The present invention relates to isooxazoles, oxazoles, thiazoles,isothiazoles and imidazoles, pharmaceutical compositions containingthese compounds and their use as endothelin receptor antagonists.

Endothelin (ET) is a highly potent vasoconstrictor peptide synthesizedand released by the vascular endothelium. Endothelin exists as threeisoforms, ET-1, ET-2 and ET-3. [Unless otherwise stated “endothelin”shall mean any or all of the isoforms of endothelin]. Endothelin hasprofound effects on the cardiovascular system, and in particular, thecoronary, renal and cerebral circulation. Elevated or abnormal releaseof endothelin is associated with smooth muscle contraction which isinvolved in the pathogenesis of cardiovascular, cerebrovascular,respiratory and renal pathophysiology. Elevated levels of endothelinhave been reported in plasma from patients with essential hypertension,acute myocardial infarction, subarachnoid hemorrhage, atherosclerosis,and patients with uraemia undergoing dialysis.

In vivo, endothelin has pronounced effects on blood pressure and cardiacoutput. An intravenous bolus injection of ET (0.1 to 3 nmol/kg) in ratscauses a transient, dose-related depressor response (lasting 0.5 to 2minutes) followed by a sustained, dose-dependent rise in arterial bloodpressure which can remain elevated for 2 to 3 hours following dosing.Doses above 3 nmol/kg in a rat often prove fatal.

Endothelin appears to produce a preferential effect in the renalvascular bed. It produces a marked, long-lasting decrease in renal bloodflow, accompanied by a significant decrease in GFR, urine volume,urinary sodium and potassium excretion. Endothelin produces a sustainedantinatriuretic effect, despite significant elevations in atrialnatriuretic peptide. Endothelin also stimulates plasma renin activity.These findings suggest that ET is involved in the regulation of renalfunction and is involved in a variety of renal disorders including acuterenal failure, cyclosporine nephrotoxicity, radio contrast induced renalfailure and chronic renal failure.

Studies have shown that in vivo, the cerebral vasculature is highlysensitive to both the vasodilator and vasoconstrictor effects ofendothelin. Therefore, ET may be an important mediator of cerebralvasospasm, a frequent and often fatal consequence of subarachnoidhemorrhage.

ET also exhibits direct central nervous system effects such as severeapnea and ischemic lesions which suggests that ET may contribute to thedevelopment of cerebral infarcts and neuronal death.

ET has also been implicated in myocardial ischemia (Nichols et al. Br.J. Pharm. 99: 597-601, 1989 and Clozel and Clozel, Circ. Res., 65:1193-1200, 1989) coronary vasospasm (Fukuda et al., Eur. J. Pharm. 165:301-304, 1989 and L{umlaut over (u)}scher, Circ. 83: 701, 1991) heartfailure, proliferation of vascular smooth muscle cells, (Takagi, Biochem& Biophys. Res. Commun.; 168: 537-543, 1990, Bobek et al., Am. J.Physiol. 258:408-C415, 1990) and atherosclerosis, (Nakaki et al.,Biochem. & Biophys. Res. Commun. 158: 880-881, 1989, and Lerman et al.,New Eng. J. of Med. 325: 997-1001, 1991). Increased levels of endothelinhave been shown after coronary balloon angioplasty (Kadel et al., No.2491 Circ. 82: 627, 1990).

Further, endothelin has been found to be a potent constrictor ofisolated mammalian airway tissue including human bronchus (Uchida etal., Eur. J. of Pharm. 154: 227-228 1988, LaGente, Clin. Exp. Allergy20: 343-348, 1990; and Springall et al., Lancet, 337: 697-701, 1991).Endothelin may play a role in the pathogenesis of interstitial pulmonaryfibrosis and associated pulmonary hypertension, Glard et al., ThirdInternational Conference on Endothelin, 1993, p. 34 and ARDS (AdultRespiratory Distress Syndrome), Sanai et al., Supra, p. 112.

Endothelin has been associated with the induction of hemorrhagic andnecrotic damage in the gastric mucosa (Whittle et al., Br. J. Pharm. 95:1011-1013, 1988); Raynaud's phenomenon, Cinniniello et al., Lancet 337:114-115, 1991); Crohn's Disease and ulcerative colitis, Munch et al.,Lancet, Vol. 339, p. 381; Migraine (Edmeads, Headache, Feb. 1991 p 127);Sepsis (Weitzberg et al., Circ. Shock 33: 222-227, 1991; Pittet et al.,Ann. Surg. 213: 262-264, 1991), Cyclosporin-induced renal failure orhypertension (Eur. J. Pharmacol., 180: 191-192, 1990, Kidney Int, 37:1487-1491, 1990) and endotoxin shock and other endotoxin induceddiseases (Biochem. Biophys. Res. Commun., 161:1220-1227, 1989, ActaPhysiol. Scand. 137: 317-318, 1989) and inflammatory skin diseases.(Clin Res. 41:451 and 484, 1993).

Endothelin has also been implicated in preclampsia of pregnancy. Clarket al., Am. J. Obstet. Gynecol. March 1992, p. 962-968; Kamor et al., N.Eng. J. of Med., Nov. 22, 1990, p. 1486-1487; Dekker et al., Eur J. Ob.and Gyn. and Rep. Bio. 40 (1991) 215-220; Schiffet al., Am. J. Ostet.Gynecol. February 1992, p. 624-628; diabetes mellitus, Takahashi et al.,Diabetologia (1990) 33:306-310; and acute vascular rejection followingkidney transplant, Watschinger et al., Transplantation Vol. 52, No. 4,pp. 743-746.

Endothelin stimulates both bone resorption and anabolism and may have arole in the coupling of bone remodeling. Tatrai et al. Endocrinology,Vol. 131, p. 603-607.

Endothelin has been reported to stimulate the transport of sperm in theuterine cavity, Casey et al., J. Clin. Endo and Metabolism, Vol. 74, No.1, p. 223-225, therefore endothelin antagonists may be useful as malecontraceptives. Endothelin modulates the ovarian/menstrual cycle,Kenegsberg, J. of Clin. Endo. and Met., Vol. 74, No. 1, p. 12, and mayalso play a role in the regulation of penile vascular tone in man, Lauet al., Asia Pacific J. of Pharm., 1991, 6:287-292 and Tejada et al., J.Amer. Physio. Soc. 1991, H1078-H1085. Endothelin also mediates a potentcontraction of human prostatic smooth muscle, Langenstroer et al., J.Urology, Vol. 149, p. 495-499.

Thus, endothelin receptor antagonists would offer a unique approachtoward the pharmacotherapy of hypertension, acute and chronic renalfailure, ischemia induced renal failure, sepsis-endotoxin induced renalfailure, prophylaxis and/or treatment of radio-contrast induced renalfailure, acute and chronic cyclosporin induced renal failure,cerebrovascular disease, cerebrovascular spasm, subarachnoid hemorrhage,myocardial ischemia, angina, congestive heart failure, acute coronarysyndrome, myocardial salvage, unstable angina, asthma, primary pulmonaryhypertension, pulmonary hypertension secondary to intrinsic pulmonarydisease, atherosclerosis, Raynaud's phenomenon, ulcers, sepsis,migraine, glaucoma, endotoxin shock, endotoxin induced multiple organfailure or disseminated intravascular coagulation, cyclosporin-inducedrenal failure and as an adjunct in angioplasty for prevention ofrestenosis, diabetes, diabetic retinopathy, retinopathy, diabeticnephropathy, diabetic macrovascular disease, atherosclerosis,preclampsia of pregnancy, bone remodeling, kidney transplant, malecontraceptives, infertility and priaprism and benign prostatichypertrophy.

SUMMARY OF THE INVENTION

This invention comprises compounds represented by Formula (I) andpharmaceutical compositions containing these compounds, and their use asendothelin receptor antagonists which are useful in the treatment of avariety of cardiovascular and renal diseases including but not limitedto: hypertension, acute and chronic renal failure, cyclosporine inducednephrotoxicity, benign prostatic hypertrophy, pulmonary hypertension,migraine, stroke, cerebrovascular vasospasm, myocardial ischemia,angina, congestive heart failure, atherosclerosis, diabetic nephropathy,diabetic retinopathy, retinopathy, diabetic macrovascular disease,atherosclerosis and as an adjunct in angioplasty for prevention ofrestenosis.

This invention further constitutes a method for antagonizing endothelinreceptors in an animal, including humans, which comprises administeringto an animal in need thereof an effective amount of a compound ofFormula (I).

In a further aspect the present invention provides a process for thepreparation of a compound of Formula (I)).

DETAILED DESCRIPTION OF THE INVENTION

The compounds of this invention are represented by structural Formula(I):

D is O or S;

E is O, S or NR₁₅;

P is tetrazol-5-yl, CO₂R₆ or C(O)NR₆)S(O)_(q)R₁₀;

R^(a) is independently hydrogen or C₁₋₆alkyl;

R₁ is independently hydrogen, Ar, C₁₋₆alkyl or C₁₋₆ alkoxy;

R₂ is Ar, C₁₋₈alkyl, C(O)R₁₄ or

R₃ and R₅ are independently R₁₃OH, C₁₋₈alkoxy, S(O)_(q)R₁₁, N(R₆)₂, NO₂,Br, F, I, Cl, CF₃, NHCOR₆, R₁₃CO₂R₇, —X—R₉—Y, —X(C(R₆)₂)OR₆,—(CH₂)_(m)X′R₈ or —X(CH₂)_(n)R₈ wherein each methylene group within—X(CH₂)_(n)R₉ may be unsubstituted or substituted by one or two—(CH₂)_(n)Ar groups;

R₄ is independently R₁₁, OH, C₁₋₅alkoxy, S(O)_(q)R₁₁, N(R₆)₂, Br, F, I,Cl or NHCOR₆, wherein the C₁₋₅alkoxy may be unsubstituted or substitutedby OH, methoxy or halogen;

R₆ is independently hydrogen or C₁₁₈alkyl;

R₇ is independently hydrogen, C₁₋₁₀alkyl, C₂₋₁₀alkenyl or C₂₋₈alkynyl,all of which may be unsubstituted or substituted by one or more OH,N(R₆)₂, CO₂R₁₂, halogen or XC₁₋₁₀alkyl; or R₇ is (CH₂)_(n)Ar;

R₈ is independently R₁₁, CO₂R₇, CO₂C(R₁₁)₂O(CO)XR₇, PO₃(R₇)₂, SO₂NR₇R₁₁,NR₇SO₂R₁₁, CONR₇SO₂R₁₁, SO₃R₇, SO₂R₇, P(O)(OR₇)R₇, CN,CO₂(CH₂)_(m)C(O)NR₆)2, C(R₁₁)₂N(R₇)₂, C(O)NR₆)₂, NR₇C(O)NR₇SO₂R₁₁, OR₆,or tetrazole which is substituted or unsubstituted by C₁₋₆alkyl;

R₉ is independently a bond, C₁₋₁₀alkylene, C₁₋₁₀alkenylene,C₁₋₁₀alkylidene, C₁₋₁₀alkynylene, all of which may be linear orbranched, or phenylene, all of which may be unsubstituted or substitutedby one of more OH, N(R₆)₂, COOH or halogen;

R₁₀ is independently C₁₋₁₀alkyl, N(R₆)₂ or Ar;

R₁₁ is independently hydrogen, Ar, C₁₋₈alkyl, C₂₋₈alkenyl, C₂₋₈alkynyl,all of which may be unsubstituted or substituted by one or more OH,CH₂OH, N(R₆)₂ or halogen;

R₁₂ is independently hydrogen, C₁₋₆alkyl, C₂₋₆alkenyl or C₂₋₇alkynyl;

R₁₃ is independently divalent Ar, C₁₋₁₀alkylene, C₁₋₁₀alkylidene,C₂₋₁₀alkenylene, all of which may be unsubstituted or substituted by oneor more OH, CH₂OH, N(R₆)₂ or halogen;

R₁₄ is independently hydrogen, C₁₋₁₀alkyl, XC₁₋₁₀alkyl, Ar or XAr;

R₁₅ is independently hydrogen, Ar, C₁₋₆alkyl, or XAr;

R₁₆ is independently C₁₋₆alkyl or phenyl substituted by one or moreC₁₋₆alkyl, OH, C₁₅alkoxy, S(O)_(q)R₆, N(R₆)₂, Br, F, I, Cl, CF₃ orNHCOR₆;

X is independently (CH₂)_(n), O, NR₆ or S(O)_(q);

X′ is independently O, NR₆ or S(O)_(q);

Y is independently CH₃ or X(CH₂)_(n)Ar;

Ar is:

naphthyl, indolyl, pyridyl, thienyl, oxazolidinyl, thiazolyl,isothiazolyl, pyrazolyl, triazolyl, tetrazolyl, imidazolyl,imidazolidinyl, thiazolidinyl, isoxazolyl, oxadiazolyl, thiadiazolyl,morpholinyl, piperidinyl, piperazinyl, pyrrolyl, or pyrimidyl; all ofwhich may be unsubstituted or substituted by one or more Z₁ or Z₂groups;

A is independently C═O, or (CR₆)2)_(m);

B is independently —CH₂- or —O—;

Z₁ and Z₂ are independently hydrogen, XR₆, C₁₋₈alkyl, (CH₂)_(q)CO₂R₆,C(O)N(R₆)₂, CN, (CH₂)_(n)OH, NO₂, F, Cl, Br, I, N(R₆)₂, NHC(O)R₆,O(CH₂)_(m)C(O)NR_(a)SO₂R₁₆ (CH₂)_(m)OC(O)NR_(a)SO₂R₁₆,O(CH₂)_(m)NR_(a)C(O)NR_(a)SO₂R₁₆ or tetrazolyl which may be substitutedor unsubstituted by one or two C₁₋₆alkyl, CF₃ or C(O)R₆;

m is independently 1 to 3;

n is independently 0 to 6;

q is independently 0, 1 or 2;

provided R₃, R^(a) and R₅ are not O—O(CH₂)_(n)Ar or O—OR₆;

or a pharmaceutically acceptable salt thereof.

All alkyl, alkenyl, alkynyl and alkoxy groups may be straight orbranched.

Halogen may be Br, Cl, F or I.

The compounds of the present invention may contain one or moreasymmetric carbon atoms and may exist in racemic and optically activeform. All of these compounds and diastereoisomers are contemplated to bewithin the scope of the present invention.

Preferred compounds are those wherein:

P is CO₂R₆; more preferably P is CO₂H.

R₁ is hydrogen.

R₂ is Ar, cyclohexyl or C₁₋₄alkyl. More preferably R₂ is a group Arwherein Ar is a group (a) or (b). In said group (a) or (b) Z₁ and Z₂ areindependently hydrogen, CO₂R₆, (CH₂)_(n)OH, C₁4alkyl or C₁₆ alkoxy, e.g.methoxy; A is preferably CH₂, and one or both Bs are preferably O.

R₃ and R₅ are independently hydrogen, CO₂R₆, OH, C₁₋₈alkoxy, C₁₋₈alkyl,N(R₆)₂, NO₂, Br, F, Cl, I, R₁₃CO₂R₇, X(CH₂)_(n)R₈, (CH₂)_(m)X′R₈, orX(CR₆)2)_(m)OR₆;

In the context of the group R₃ and R₅ preferably do not representhydrogen. In particular in the group R₃ preferably represents Br, Cl,C₁₋₈alkoxy e.g. methoxy; X(CH₂)_(n)R₈, wherein X preferably representsO, n is 0, 1, or 2, and R₈ is preferably selected from:

CO₂R₆ wherein R₆ is preferably hydrogen;

OR₆ wherein R₆ is preferably H;

tetrazolyl optionally substituted by C₁₋₈alkyl e.g. ethyl;

CONR₇SO₂R₁₁ wherein R₇ is H or C₁₋₈alkyl e.g. methyl, R₁₁ preferably isC₁₋₈alkyl (e.g. methyl, isopryl, or t-butyl) or phenyl optionallysubstituted by Br, Cl, F, C₁₋₈alkyl e.g. methyl; or R₈ is phenyl orpyridyl substituted by one or more Br, Cl, CO₂H, CH₂OH.

R₅ is C₁₋₈alkoxy e.g. methoxy, or N(R₆)₂ wherein R₆ preferably is H ormethyl.

R₄ is hydrogen, OH, C₁₋₅-alkoxy, N(R₆)₂, Br, F, Cl, I, NHCOCH₃, or S(O)qC₁₋₅alkyl wherein the C₁₋₅alkyl may be unsubstituted or substituted byOH, methoxy or halogen. R₄ is more preferably hydrogen; R₆ is hydrogenor C₁₋₈alkyl e.g. methyl and ethyl;

R₇ is hydrogen, C₁₋₁₀alkyl, C₂₋₁₀alkenyl or C₂₋₈alkynyl, all of whichmay be unsubstituted or substituted by one or more OH, N(R₆)₂, CO₂R₁₂,halogen, or R₇ is (CH₂)_(n)Ar. When R₇ is (CH₂)_(n)Ar, n is preferablyzero or 1 and Ar is preferably phenyl substituted or unsubstituted byhalogen or C₁₋₅ alkoxy.

R₁₁ is hydrogen, phenyl, pyridyl wherein the phenyl and pyridyl may besubstituted or unsubstituted by one or two C₁₋₄alkyl groups; C₁₋₈alkyl,C₂₋₈alkenyl, C₂₋₈alkynyl, all of which may be substituted orunsubstituted by one or more OH, CH₂OH, N(R₆)₂, or halogen;

R₁₂ is hydrogen or C₁₋₆alkyl.

R₁₃ is phenyl, pyridyl, or C₂₋₁₀alkylene, all of which may beunsubstituted or substituted by one or more CO₂R₆, OH, CH₂OH, N(R₆)₂, orhalogen;

R₁₅ is preferably hydrogen or C₁₋₆alkyl e.g. ethyl, isopropyl, n-butyl,cyclopropylmethyl or cyclopropylethyl.

The preferred compounds are:

(E)-3-[1-n-Butyl-5-[2-(2-carboxyphenyl)methoxy-4-methoxyphenyl]-1H-imidazol-4-yl]-2-[(2-methoxy-4,5-methylenedioxy)phenylmethyl]-prop-2-enoicacid;

(E)-alpha-[[5-[2-[(2-carboxyphenyl)methoxy]-4methoxyphenyl]isoxazol-4-yl]methylene]-6-methoxy-1,3-benzodioxole-5-propanoicacid;

(E)-alpha-[[3-[2-[(2-carboxyphenyl)methoxy]-4-methoxyphenyl]isoxazol-4-yl]methylene]-6-methoxy-1,3-benzodioxole-5-propanoicacid; and

(E)-alpha-[[3-Butyl-4-[2-[(2-carboxyphenyl)methoxy]4methoxyphenyl]isoxazol-5-yl]methylene]-6-methoxy-1,3-benzodioxole-5-propanoicacid.

Compounds of the Formula (Ie),

in which R^(a) is H and D is O, can be prepared by Knoevenagelcondensation of a 3-formyl chromone of Formula (2)

with a half acid of Formula (3), wherein R₁₆ is allyl

in a solvent such as benzene at reflux, in the presence of piperidiniumacetate with azeotropic removal of water using a Dean-Stark apparatus toafford an ester of Formula (4).

Compounds of Formula (2) are commercially available or may be preparedby treatment of a phenol of Formula (5)

with boron trifluoride etherate in acetic anhydride followed bytreatment with Vilsmeier reagent in dimethyl formamide according to theprocedure of Högberg et al. (Acta Chem. Scand. 1984, B38, 359-366)

Reaction of compound (4) with hydroxylamine hydrochloride (NH₂OH . HCl)in a suitable solvent such as aqueous ethanol at reflux and in thepresence of a base such as sodium acetate provides a phenol of Formula(6).

Alkylation of a phenol of Formula (6) using a bromide of Formula (7),wherein R₁₆ is allyl

in the presence of a base such as sodium hydride in a solvent such asdimethylformamide affords a compound of Formula (8).

Deprotection of diallyl ester of Formula (8) using triethylsilane in thepresence of a catalytic amount oftetrakis(triphenylphosphine)palladium(0) in a suitable solvent such astetrahydrofuran at reflux affords, after acidification with acetic acid,an acid of the Formula (Ie), wherein R^(a) is H, P is CO₂H and D is O.

Alternatively, compounds of Formula (Ie) can be prepared starting fromthe reaction of a keto ester of Formula (9), wherein R₁₆ is allyl

with an acyl chloride of Formula (10)

in the presence of a base such as sodium in a solvent such as benzene,to provide a compound of Formula (12)

Compound of Formula (12) can be treated with hydroxylamine hydrochloride(NH₂OH . HCl) in a suitable solvent such as pyridine at reflux, toprovide an isoxazole of Formula (13).

Conversion of an allyl ester of Formula (13) using triethylsilane in thepresence of a catalytic amount oftetrakis(triphenylphosphine)palladium(0) in a suitable solvent such astetrahydrofuran at reflux affords, after acidification with acetic acidan acid of the Formula (14).

Compound of Formula (14) can be converted to the correspondingN-methyl-O-methylcarboxamide of Formula (15)

upon treatment with methyl choroformate followed byN,O-dimethylhydroxylamine hydrochloride in the presence of a base suchas N-methylpiperidine. Compound of Formula (15) can be treated with anorganometallic reagent of Formula (16)

R^(a)—M  (16)

wherein R^(a) is C₁₋₆alkyl and M is either Li or MgCl, following theprocedure of Nahm and Weinreb (Tetrahedron Lett. 1981, 39, 3815), toprovide a compound of Formula (17), wherein R^(a) is C₁₆alkyl.

Alternatively, a compound of Formula (17), wherein R^(a) is H, can beobtained by treatment of carboxamide of Formula (15) with lithiumaluminum hydride in a solvent such as anhydrous ether.

Reaction of compound of Formula (17) with the the lithium enolate of anester of Formula (18), wherein R₁₆ is allyl

generated by by treatment of (18) with lithium diisopropylamide at −78°C. under an inert atmosphere in a solvent such as tetrahydrofuran,provides an alcohol of Formula (19)

Dehydration of compound of Formula (19) with acetic anhydride followedby treatment with a base such as 1,8-diazabicyclo[5.4.0]undec-7-eneprovides a compound of Formula (20)

Alternatively, reaction of compound (17), wherein R^(a) is C₁₋₆alkyl,with Lawesson's reagent[2,4bis(4-methoxyphenyl)-1,3-dithia-2,4-diphosphetane-2,4-disulfide] ina suitable solvent such as tetrahydrofuran affords a thione of Formula(21).

Reaction of a compound of Formula (21) with a diazoester of Formula(22), wherein R₁₆ is allyl

in refluxing tetrahydrofuran affords thiirane (23).

A diazoester of Formula (22) can be prepared from the correspondingester (18) by treatment with lithium diisopropylamide at −78° C. in asolvent such as anhydrous tetrahydrofuran, followed by the addition ofethyl formate to produce a formylated ester of structure (24).

Compounds of Formula (24) can be treated with an arylsulfonylazide suchas 4 carboxyphenylsulfonyl azide in the presence of a base such astriethylamine followed by treatment with a base such as aqueouspotassium hydroxide to afford diazoesters of type (22).

Treatment of a thiirane of Formula (23) with trimethylphosphite atreflux in a solvent such as chloroform provides compounds of Formula(20), wherein R^(a) is C₁₋₆alkyl.

Deprotection of allyl ester of Formula (20) using triethylsilane in thepresence of a catalytic amount oftetrakis(triphenylphosphine)palladium(0) in a suitable solvent such astetrahydrofuran at reflux affords, after acidification with acetic acid,an acid of the Formula (Ie), wherein P is CO₂H and D is O.

Compounds of Formula (Id), wherein D is O, can be prepared starting fromcompound (12) by treatment with hydroxylamine hydrochloride (NH₂OH .HCl) in a suitable solvent such as methanol, following the procedure ofNair and Wadodkar, Indian J. Chem., Sect B, 1982, 21, 573, to provide anisoxazole of Formula (25).

Compound of Formula (25) can be subsequently converted to compounds ofFormula (Id) following the same synthetic scheme as the one describedabove for the conversion of compound (13) to compound (Ie).

Compounds of Formula (If) can be prepared starting by commerciallyavailable ketones of Formula (26)

by reaction with diallyl oxalate of Formula (27)

in the presence of a base such as sodium in a solvent such as allylalcohol to produce a diketone of Formula (28), wherein R₁₆ is allyl.

Reaction of a diketone of Formula (28) with hydroxylarn-inehydrochloride (NH₂OH . HCl) in a suitable solvent such as pyridine atreflux provides an isoxazole of Formula (29).

Deprotection of allyl ester of Formula (29) using triethylsilane in thepresence of a catalytic amount oftetrakis(triphenylphosphine)palladium(0) in a suitable solvent such astetrahydrofuran at reflux affords, after acidification with acetic acid,an acid of the Formula (30),

which can be subsequently converted to the correspondingN-methoxy-N-methylamide of Formula (31)

by treatment with methyl chorofonnate followed byN,O-ditnethylhydroxylamine hydrochloride in the presence of a base suchas N-methylpiperidine. Compound of Formula (31) can be treated with anorganometallic reagent of Formula (16) to provide a compound of Formula(32), wherein R^(a) is C₁₋₆alkyl.

Alternatively, compound (31) can be treated with with lithium aluminumhydride in a solvent such as diethyl ether to provide a compound ofFormula (32), wherein R^(a) is H.

Reaction of compound of Formula (32) with the the lithium enolate of anester of Formula (18) provides an alcohol of Formula (33)

Dehydration of compound of Formula (33) with acetic anhydride followedby treatment with a base such as 1,8-diazabicyclo[5.4.0]undec-7-eneprovides a compound of Formula (34)

Alternatively, reaction of compound (32), wherein R^(a) is C₁₋₆alkyl,with Lawesson's reagent in a suitable solvent such as tetrahydrofuranaffords a thione of Formula (35),

which can be treated with diazoester (22) in refluxing tetrahydrofuranto provide a thiirane of Formula (36).

Treatment of a thiirane of Formula (36) with trimethylphosphite atreflux in a solvent such as chloroform provides compounds of Formula(34), wherein R^(a) is C₁₋₆alkyl.

Deprotection of allyl ester of Formula (34) using triethylsilane in thepresence of a catalytic amount oftetrakis(triphenylphosphine)palladium(0) in a suitable solvent such astetrahydrofuran at reflux affords, after acidification with acetic acid,an acid of the Formula (Ii), wherein P is CO₂H and D is O.

Compounds of Formula (Ig) can be prepared by a process which comprisestreating an aryl halide of Formula (37), where Z is I, Br, or Cl

with an appropriate alkyllithium reagent such as n-butyllithium intetrahydrofuran by addition of a borate such as triisopropyl borate andacidic work up affords a boronic acid of Formula (38)

Reaction of a boronic acid of Formula (38) with a compound of Formula(39)

in the presence of a suitable base such as potassium carbonate with apalladium catalyst such as tetrakis(triphenylphosphine)palladium(0) in amixture of toluene, ethanol and water at approximately 80-100° C.provides a compound of Formula of (40)

Knoevenagel condensation of an aldehyde of Formula (40) with a half acidof Formula (3), wherein R₁₆ is C₁₋₈ alkyl, in a solvent such as benzenear reflux, in the presence of piperidinium acetate with azeotropicremoval of water using a Dean-Stark apparatus, affords an ester ofFormula (41)

Saponification of an ester of Formula (41) using aqueous sodiumhydroxide in a solvent such as ethanol provides, after acidificationwith aqueous hydrochloric acid, an acid of Formula (Ig), wherein R^(a)is H and P is CO₂H.

The invention also is a process for preparing compounds of Formula (I)by:

(a) Reaction of a compound of Formula (II)

or a protected form or precursor thereof (as defined hereinafter) with acompound of Formula (3)

(wherein R₂ and R₁₆ are as defined for Formula (I) hereinabove);followed if necessary or desired by:

(b) conversion of one compound of Formula (1) into a different compoundof Formula (I) e.g.

(i) when Formula (I) contains a group CO₂R₆, CO₂R₇ or CO₂R₁₂ wherein R₆,R₇ or R₁₂ is alkyl, conversion to a corresponding compound where R₆, R₇or R₁₂ represents hydrogen;

(ii) when Formula (I) contains a hydroxy group (e.g. in R₃, R₄ or R₅)conversion to a different group, e.g. a group (CH₂)Ar where Ar isoptionally substituted phenyl, by method well known in the art; and/or

(c) salt formation.

It will be appreciated by those skilled in the art that thesubstitutents R₃, R₄, R₅a R₁₅ and Z₁ and Z₂ may be introduced at anyappropriate stage of the synthesis, preferably at an early stage, usingmethods well known in the art. In some of the reactions depicted above,particularly those in the early stages of the overall synthesis, one ormore of the substitutents may therefore represent a precursor for theeventual substituent. A precursor for any of the substitutents means agroup which may be derivatised or converted into the desired group. Itwill be further appreciated that it may be necessary or desirable toprotect certain of these substitutents (or their precursors) at variousstages in the reaction sequence. Suitable precursors and protectinggroups are well known to those skilled in the art, as are methods fortheir conversion or removal respectively.

In order to use a compound of the Formula (I) or a pharmaceuticallyacceptable salt thereof for the treatment of humans and other mammals itis normally formulated in accordance with standard pharmaceuticalpractice as a pharmaceutical composition.

Compounds of Formula (I) and their pharmaceutically acceptable salts maybe administered in a standard manner for the treatment of the indicateddiseases, for example orally, parenterally, sub-lingually,transdermally, rectally, via inhalation or via buccal administration.

Compounds of Formula (I) and their pharmaceutically acceptable saltswhich are active when given orally can be formulated as syrups, tablets,capsules and lozenges. A syrup formulation will generally consist of asuspension or solution of the compound or salt in a liquid carrier forexample, ethanol, peanut oil, olive oil, glycerine or water with aflavouring or colouring agent. Where the composition is in the form of atablet, any pharmaceutical carrier routinely used for preparing solidformulations may be used. Examples of such carriers include magnesiumstearate, terra alba, talc, gelatin, agar, pectin, acacia, stearic acid,starch, lactose and sucrose. Where the composition is in the form of acapsule, any routine encapsulation is suitable, for example using theaforementioned carriers in a hard gelatin capsule shell. Where thecomposition is in the form of a soft gelatin shell capsule anypharmaceutical carrier routinely used for preparing dispersions orsuspensions may be considered, for example aqueous gums, celluloses,silicates or oils and are incorporated in a soft gelatin capsule shell.

Typical parenteral compositions consist of a solution or suspension ofthe compound or salt in a sterile aqueous or non-aqueous carrieroptionally containing a parenterally acceptable oil, for examplepolyethylene glycol, polyvinylpyrrolidone, lecithin, arachis oil, orsesame oil.

Typical compositions for inhalation are in the form of a solution,suspension or emulsion that may be administered as a dry powder or inthe form of an aerosol using a conventional propellant such asdichlorodifluoromethane or trichlorofluoromethane.

A typical suppository formulation comprises a compound of Formula (1) ora pharmaceutically acceptable salt thereof which is active whenadministered in this way, with a binding and/or lubricating agent, forexample polymeric glycols, gelatins, cocoa-butter or other low meltingvegetable waxes or fats or their synthetic analogues.

Typical transdermal formulations comprise a conventional aqueous ornon-aqueous vehicle, for example a cream, ointment, lotion or paste orare in the form of a medicated plaster, patch or membrane. Preferablythe composition is in unit dosage form, for example a tablet, capsule ormetered aerosol dose, so that the patient may administer to themselves asingle dose.

Each dosage unit for oral administration contains suitably from 0.1 mgto 500 mg/Kg, and preferably from 1 mg to 100 mg/Kg, and each dosageunit for parenteral administration contains suitably from 0.1 mg to 100mg, of a compound of Formula (I) or a pharmaceutically acceptable saltthereof calculated as the free acid. Each dosage unit for intranasaladministration contains suitably 1400 mg and preferably 10 to 200 mg perperson. A topical formulation contains suitably 0.01 to 1.0% of acompound of Formula (I).

The daily dosage regimen for oral administration is suitably about 0.01mg/Kg to 40 mg/Kg, of a compound of Formula (I) or a pharmaceuticallyacceptable salt thereof calculated as the free acid. The daily dosageregimen for parenteral administration is suitably about 0.001 mg/Kg to40 mg/Kg, of a compound of the Formula (I) or a pharmaceuticallyacceptable salt thereof calculated as the free acid. The daily dosageregimen for intranasal administration and oral inhalation is suitablyabout 10 to about 500 mg/person. The active ingredient may beadministered from 1 to 6 times a day, sufficient to exhibit the desiredactivity.

No unacceptable toxicological effects are expected when compounds of theinvention are administered in accordance with the present invention.

The biological activity of the compounds of Formula (I) are demonstratedby the following tests:

I. Binding Assay

A) CHO cell membrane preparation.

CHO cells stably transfected with human ET_(A) and ET_(B) receptors weregrown in 245 mm×245 mm tissue culture plates in Dulbecco's modifiedEagle's medium supplemented with 10% fetal bovine serum. The confluentcells were washed with Dulbecco's phosphate-buffered saline containing aprotease inhibitor cocktail (5 mM EDTA, 0.5 mM PMSF, 5 ug/ml ofleupeptin and 0.1 U/ml of aprotinin) and scraped in the same buffer.After centrifugation at 800×g, the cells were lysed by freezing inliquid nitrogen and thawing on ice followed by homogenization (30 timesusing a glass dounce homogenizer) in lysis buffer containing 20 mM TrisHCl, pH 7.5, and the protease inhibitor cocktail. After an initialcentrifugation at 800× g for 10 min to remove unbroken cells and nuclei,the supernatants were centrifuged at 40,000×g for 15 min and the pelletwas resuspended in 50 mM Tris HCl, pH 7.5, and 10 mM MgCl₂ and stored insmall aliquots at −70° C. after freezing in liquid N₂. Protein wasdetermined by using the BCA method and BSA as the standard.

(B) Binding studies.

[¹²⁵I]ET-1 binding to membranes prepared from CHO cells was performedfollowing the procedure of Elshourbagy et al. (1993). Briefly, the assaywas initiated in a 100 ul volume by adding 25 ul of [¹²⁵I]ET-1 (0.2-0.3nM) in 0.05% BSA to membranes in the absence (total binding) or presence(nonspecific binding) of 100 nM unlabeled ET-1. The concentrations ofmembrane proteins were 0.5 and 0.05 ug per assay tube for ETA and ETBreceptors, respectively. The incubations (30° C., 60 min) were stoppedby dilution with cold buffer (20 mM Tris HCl, pH 7.6, and 10 mM MgCl₂)and filtering through Whatman GF/C filters (Clifton, N.J.) presoaked in0.1% BSA. The filters were washed 3 times (5 ml each time) with the samebuffer by using a Brandel cell harvester and were counted by using agamma counter at 75% efficiency.

The following examples are illustrative and are not limiting of thecompounds of this invention.

EXAMPLE 1 (E)-Ethylalpha-[[3-[4methoxy-2-[[2-(methoxycarbonyl)phenyl]methoxy]-phenyl]isoxazol-4-yl]methylene]-6-methoxy-1,3-benzodioxole-5-propanoate

a) (E)-Ethyl6-Methoxy-alpha-[(7-methoxy-4-oxo-4H-1-benzopyran-3-yl)methylene]-1,3-benzodioxole-5-propanoate

A solution of 3-formyl-7-methoxychromone (0.67 g, 3.3 mmol) and ethylhydrogen 2-[(6-methoxy-3,4methylenedioxy)benzyl]malonate (0.89 g, 3.0mmol) in benzene (30 mL) was treated with piperidine (0.15 mL, 1.5 mmol)followed by acetic acid (0.085 mL, 1.5 mmol). The reaction was stirredat reflux equipped with a Dean Stark apparatus for 2 h. The mixture wascooled then extracted with EtOAc (200 mL). The organic extract waswashed successively with saturated NaHCO₃ and brine, dried (MgSO₄) andconcentrated under vacuum. The resulting residue was purified by columnchromatography (silica gel, EtOAc/hexane, gradient 75:25 to 70:30) toafford a material consisting of a 1.2:1 mixture of E:Z enoates as an oil(1.02 g, 78%). Recrystallization of this material from ethanol affordsthe title compound as the E-isomer, exclusively.

Data for the the E-isomer: mp 140-141° C.; MS (ESI) m/z 439 (M+H)⁺.Anal. Calcd for C₂₄H₂₂O₈: C, 65.75; H, 5.06. Found: C, 65.56; H, 4.99.

b) (E)-Ethyl(E)-alpha-[[3—(2-hydroxy-4-methoxyphenyl)isoxazol-4-yl]methylene]-6-methoxy-1,3-benzodioxole-5-propanoate

A solution of the compound of Example 1(a) (0.701 g, 1.6 mmol of a 1:1E:Z mixture), hydroxylamine hydrochloride (0.222 g, 3.2 mmol) and sodiumacetate trihydrate (0.870 g, 6.4 mmol) in a mixture of 9:1 EtOH:H₂O (32mL) was stirred at reflux for 1 h. The reaction mixture was cooled andsubsequently partitioned between EtOAc (150 mL) and aqueous pH 7 buffer.The organic extract was washed with brine, dried (Na₂SO₄) andconcentrated under vacuum. The resulting residue was purified by columnchromatography (silica gel, CH₂Cl₂/hexane/EtOAc, 90:5:5 to 80:10:10) toafford the title compound (245 mg, 34%), that crystallized uponstanding. mp 122-123.5° C. MS (ESI) m/z 454 (M+H)⁺.

c) (E)-Ethylalpha-[[3-[4-methoxy-2-[[2-(methoxycarbonyl)phenyl]methoxy]-phenyl]isoxazol-4-yl]methylene]-6-methoxy-1,3-benzodioxole-5-propanoate

A solution of the compound of Example 1(b) (0.252 g, 0.58 mmol) in DMF(1.5 mL) was added dropwise to a slurry of NaH (0.022 g, 0.93 mmol) inDMF (1.4 mL) at room temperature. The reaction was stirred for 3 min atwhich time was added methyl 2-(bromomethyl)benzoate (0.21 g, 0.93 mmol)and stirring continued for 1 h at room temperature. The mixture wasquenched with aqueous pH 7 buffer, then diluted with EtOAc. The organicextract was washed with brine, dried (Na₂SO₄) and concentrated undervacuum. The resulting residue was purified by column chromatography(silica gel, 75:25 hexane/EtOAc) to afford the title compound (84.5 mg,24%) as a white solid. mp 135-137° C. MS (ESI) m/z 602 (M+H)⁺.

EXAMPLE 2(E)-3-[1-n-Butyl-5-[2-(2-carboxyphenyl)methoxy-4-methoxyphenyl]-1H-imidazol-4-yl]-2-[(2-methoxy-4,5-methylenedioxy)phenylmethyl]-2-propenoicacid

a) Ethyl 2-amino-2-cyanoacetate

To aluminum foil (25 g) was added a solution of mercury(II) chloride (10g, 0.37 mol) in water (1 L). The mixture was swirled for 5 min, and thenthe turbid solution was decanted off. The resulting aluminum amalgam waswashed successively with water, methanol and diethyl ether. To amalgamsuspended in diethyl ether (500 mL) at 0° C., was added a solution ofethyl 2-hydroxyimino-2-cyanoacetate (100 g, 0.70 mol) in diethyl ether(300 mL), followed by water (50 mL), maintaining a gentle reflux. After1 h of stirring, the mixture was filtered and the filtrate was washedwith water, brine and dried (Na₂SO₄). Removal of the solvent gave thetitle compound as a white solid (67 g, 74%). ¹H NMR (250 MHz, CD₃OD) δ4.45 (m, 2H), 2.49 (s, 1H), 1.38 (m, 3H).

b) Ethyl 5-amino-1-n-butyl-1H-imidazole-4-carboxylate

A solution of ethyl 2-amino-2-cyanoacetate (0.20 g, 1.56 mmol) andtriethyl formate (0.30 mL, 1.72 mmol) in acetonitrile (5 mL) wasrefluxed for 1 h. After concentrating the residue was dissolved in asolution of acetonitrile (5 mL) and n-butylamine (0.17 mL, 1.72 mmol).The resulting mixture was stirred at reflux for 1 h. The solvents wereremoved under reduced pressure and the residue was partitioned betweenwater and ethyl acetate. The organic layer was separated and washed withbrine and dried (Na₂SO₄). After removing the solvent under reducedpressure, flash chromatography (1:1 ethyl acetate/hexane) of the residuegave 0.12 g, 40% of the title compound as an oil: ¹H NMR (250 MHz,CDCl₃) δ 6.97 (s, 1H), 5.10 (s, 2H), 4.31 (q, 2H), 3.75 (t, 2H), 1.65(m, 2H), 1.35 (m, 5H), 0.97 (t, 3H); MS(ESI) m/e 212.2 [M+H]⁺.

c) Ethyl 5-bromo-1-n-butyl-1H-imidazole-4-carboxylate

To a solution of ethyl 5-amino-1-n-butyl-1H-imidazole-4-carboxylate(0.05 g, 0.24 mmol) in bromoform (5 mL) was added butyl nitrite (0.10mL, 0.71 mmol). The reaction mixture was stirred at reflux for 5 h.After an aqueous work up, extracting with ethyl acetate, the combinedorganic extracts were washed with brine and dried (Na₂SO₄). Afterremoving the solvent under reduced pressure, flash column chromatography(1:1 ether/hexane) of the residue gave the title compound as an oil(0.03 g, 46%). ¹H NMR (250 MHz, CDCl₃) δ 7.50 (b, 1H), 4.41 (q, 2H),3.95 (t, 2H), 1.70 (quintet, 2H), 1.40 (m, 5H), 1.00 (t, 3H).

d) Ethyl5—(2-methoxymethoxy-4-methoxyphenyl)-1-n-butyl-1H-imidazole-4-carboxylate

A mixture of ethyl 5-bromo-1-n-butyl-1H-imidazole-4-carboxylate (0,10 g,0.37 mmol), 2-methoxymethoxy-4methoxyphenylboronic acid (0.16 g, 0.73mmol), sodium carbonate (0.08 g, 0.73 mmol) andtetrakis(triphenylphosphine)-palladium(0) (0.04 g) in 12 mL oftoluene/ethanol/water (10/1/1) was stirred at reflux for 24 h. After anaqueous work up, extracting with ethyl acetate (3×20 mL), the combinedorganic extracts were washed with brine and dried (Na₂SO₄). Afterremoving the solvent under reduced pressure, flash column chromatography(1:1 ethyl acetate/hexane) of the residue afforded the title compound asan oil (0.06 g, 46%). ¹H NMR (250 MHz, CDCl₃) δ 7.53 (s, 1H), 7.09 (d,1H), 6.75 (d, 1H), 6.60 (dd, 1H), 5.05 (q, 2H), 4.21 (q, 2H), 3.85 (s,3H) 3.80 (t, 2H), 3.30 (s, 3H) 1.60 (quintet, 2H), 1.30 (m, 5H), 0.80(t, 3H).

e)1-n-Butyl-4-hydroxymethyl-5—(2-methoxymethoxy-4-methoxyphenyl)-1H-imidazole

To a solution of ethyl1-n-butyl-5-(2-methoxymethoxy-4-methoxyphenyl)-1H-imidazole-4-carboxylate(0.06 g, 0.17 mmol) in THF (5 mL) was added LAH (0.20 mL) at roomtemperature. The mixture was stirred for 2 h. After an aqueous work up,extracting with ethyl acetate (3×20 mL), the combined organic extractswere washed with brine and dried (Na₂SO₄). After removing the solventunder reduced pressure, flash column chromatography (1:1 ethylacetate/hexane) of the residue afforded the title compound as an oil(0.05 g, 96%). ¹H NMR (400 MHz, CDCl₃) δ 7.53 (s, 1H), 7.19 (d, 1H),6.85 (d, 1H), 6.65 (dd, 1H), 5.05 (d, 2H), 4.41 (dd, 2H), 3.85 (s, 3H)3.80 (t, 2H), 3.45 (s, 3H) 3.23 (b, 1H), 1.55 (quintet, 2H), 1.25(quintet, 2H), 0.83 (t, 3H).

f)1-n-Butyl-5—(2-methoxymethoxy-4-methoxyphenyl)-1H-imidazole-4-carboxaldehyde

To a solution1-n-butyl-4-hydroxymethyl-5-(2-methoxymethoxy-4-methoxy-phenyl)-1H-imidazole(0.05 g, 0.16 mmol) in toluene (5 mL) was added manganese oxide (0.04 g,0.47 mmol). The mixture was stirred for 5 h at room temperature. Themixture was filtered and the filtrate was evaporated to dryness. Flashcolumn chromatography (1:4 ethyl acetate/hexane) of the residue affordedthe title compound as an oil (0.05 g, 94%). ¹H NMR (250 MHz, CDCl₃) δ9.65 (s, 1H), 7.58 (s, 1H), 7.13 (d, 1H), 6.80 (d, 1H), 6.65 (dd, 1H),5.05 (s, 2H), 3.90 (s, 3H) 3.80 (t, 2H), 3.35 (s, 3H), 1.55 (quintet,2H), 1.25 (quintet, 2H), 0.83 (t, 3H).

g) Ethyl(E)-3-[1-n-butyl-5-[2-(2-methoxymethoxy)-4-methoxyphenyl]-1H-imidazol-4-yl]-2-[(2-methoxy-4,5-methylenedioxy)phenylmethyl]-2-propenoate

A solution of1-n-butyl-5—(2-methoxymethoxy-4-methoxyphenyl)-1H-imidazol-4-carboxaldehyde(0.40 g, 1.40 mmol), ethyl hydrogen2-(2-methoxy-4,5-methylenedioxybenzyl) malonate (1.00 g, 3.50 mmol),piperidine(0.07 mL-, 0.70 mmol) and acetic acid (0.04 mL, 0.70 mmol) inbenzene (20 mL), equipped with a Dean-Stark apparatus, was stirred atreflux for 24 h. The solvent was removed under reduced pressure and thecrude residue was dissolved in ethyl acetate and washed with 10% sodiumcarbonate solution, water and dried (Na₂SO₄). After removing thesolvent, flash column chromatography of the residue (silica gel, 50%ethyl acetate/hexane) yielded the title compound as a brown oil (0.24 g,33%). ¹H NMR (250 MHz, CDCl₃) δ 7.63 (s, 1H), 7.35 (s, 1H), 7.13 (d,1H), 6.70 (d, 1H), 6.65 (m, 2H), 6.51 (m, 2H), 5.75 (s, 2H), 5.05 (s,2H), 4.07 (q, 2H), 3.87 (s, 3H) 3.77 (t, 3H), 3.35 (s, 3H), 1.55(quintet, 2H), 1.25 (quintet, 2H), 1.10 (t, 3H), 0.83 (t, 3H).

h) Ethyl(E)-3-[1-n-butyl-5—(2-hydroxy-4-methoxy)phenyl-1H-imidazol-4-yl]-2-[(2-methoxy-4,5-methylenedioxy)phenylmethyl]-2-propenoate

To a solution of the ethyl(E)-3-[1-n-butyl-5-(2-methoxymethoxy-4-methoxy-phenyl)-1H-imidazolyl]-2-[(2-methoxy-4,5-methylenedioxy)phenylmethyl]-2-propenoate(0.20 g, 0.38 mmol) in ethanol (25 mL) was added a catalytic amount ofconcentrated HCl . After stirring at reflux for 5 h the solvent wasremoved under reduced pressure. The residue was dissolved in ethylacetate and washed with sat'd. sodium bicarbonate and dried (Na₂SO₄).After removing the solvent flash chromatography of the residue (silicagel, 50% ethyl acetate/hexane) gave the title compound as a brown oil(0.18 g, 87%). ¹H NMR (250 MHz, CDCl₃) δ 7.53 (s, 1H), 7.35 (s, 1H),7.00 (d, 1H), 6.60 (d, 1H), 6.55 (m, 2H), 6.51 (m, 2H), 5.85 (s,2H),4.39 (dd, 2H), 4.07 (q, 2H), 3.87 (s, 3H) 3.77 (t, 3H), 1.50(quintet, 2H), 1.15 (m, 5H), 0.83 (t, 3H).

i) Ethyl(E)-3-[1-n-butyl-5-[2-(2-methoxycarbonyl)phenylmethoxy-4-methoxy-phenyl]-1H-imidazol-4-yl]-2-[(2-methoxy-4,5-methylenedioxy)phenylmethyl]-2-propenoate

To a solution of the ethyl(E)3-[1-n-butyl-5—(2-hydroxy-4-methoxyphenyl)-1H-imidazol-4-yl]-2-[(2-methoxy-4,5-methylenedioxy)phenylmethyl]-2-propenoate(0.08 g, 0.16 mmol) and 2-methyl carboxylate benzylbromide (0.09 g, 0.38mmol) in DMF (5 mL) was added sodium hydride (0.01 g, 0.47 mmol) at 0°C. The reaction stirred at room temperature for 4h. After an aqueouswork up, extracting with ethyl acetate (3×15 mL), the combined organicextracts were washed and dried (Na₂SO₄). After removing the solventunder reduced pressure, flash column chromatography (1:1 ethylacetatelhexane) of the residue afforded the title compound as an oil(0.05 g, 46%). ¹H NMR (250 MHz, CDCl₃) δ 7.98 (d, 1H), 7.60 (s, 1H),7.48 (m, 2H), 7.35 (m, 2H), 7.15 (d, 1H), 6.65 (m, 2H), 6.50 (s, 2H),5.83 (d, 2H), 5.45 (s, 2H),4.49 (q, 2H), 4.07 (q, 2H), 3.90 (s, 3H) 3.87(s, 3H), 3.78 (s, 3H), 1.52 (quintet, 2H), 1.15 (m, 3H), 0.75 (t, 3H).

j)(E)-3-[1-n-Butyl-5-[2-(2-carboxyphenylmethoxy)-4-methoxyphenyl]-1H-imidazol-4-yl]-2-[(2-methoxy-4,5-methylenedioxy)phenylmethyl]-2-propenoicacid

To a solution of the ethyl(E)-3-[1-n-butyl-5-[2-(2-methoxycarbonyl)phenyl-methoxy-4methoxyphenyl]-1H-imidazol-4yl]-2-[(2-methoxy-4,5-methylene-dioxy)phenylmethyl]-2-propenoate(0.04 g, 0.07 mmol) in methanol (5 mL) was added a solution of sodiumhydroxide (0.01 g, 0.25 mmol) in water (2 mL). The mixture stirred atreflux for 18 h. The methanol was removed under reduced pressure and theaqueous layer was washed with ether. The aqueous layer was acidifiedwith concentrated HCl to pH 1 and extracted with ethyl acetate (3×50mL). The combined organic extracts were washed with water, brine anddried (Na₂SO₄). Removal of the solvent gave a white solid.Recrystallization from methanol yielded the title compound as a whitesolid (0.03 g, 72%): ¹H NMR (400 MHz CD₃OD) δ 7.98 (d, 1H), 7.80 (s,1H), 7.48 (s, 1H), 7.35 (m, 3H), 7.15 (d, 1H), 6.65 (m, 2H), 6.50 (s,1H), 6.38 (s, 1H), 5.78 (s, 2H), 5.55 (dd, 2H), 4.10 (s, 2H), 3.85 (s,3H) 3.65 (s, 3H), 1.50 (quintet, 2H), 1.11 (quintet, 2H), 0.70 (t, 3H);MS(ESI) m/e 615.2 [M+H]⁺; mp: 178° C. (methanol); Anal. (C₃₄H₃₄N₂O₉)calcd: C, 66.37; H, 5.58; N, 4.56. found: C, 66.10; H, 5.32; N, 4.19.

EXAMPLE 3

Formulations for pharmaceutical use incorporating compounds of thepresent invention can be prepared in various forms and with numerousexcipients. Examples of such formulations are given below.

Inhalant Formulation

A compound of Formula I, (1 mg to 100 mg) is aerosolized from a metereddose inhaler to deliver the desired amount of drug per use.

Tablets/Ingredients Per Tablet 1. Active ingredient 40 mg (Cpd of Form.I) 2. Corn Starch 20 mg 3. Alginic acid 20 mg 4. Sodium Alginate 20 mg5. Mg stearate 1.3 mg 2.3 mg

Procedure for tablets:

Step 1 Blend ingredients No. 1, No. 2, No. 3 and No. 4 in a suitablemixer/blender.

Step 2 Add sufficient water portion-wise to the blend from Step 1 withcareful mixing after each addition. Such additions of water and mixinguntil the mass is of a consistency to permit its conversion to wetgranules.

Step 3 The wet mass is converted to granules by passing it through anoscillating granulator using a No. 8 mesh (2.38 mm) screen.

Step 4 The wet granules are then dried in an oven at 140° F. (60° C.)until dry.

Step 5 The dry granules are lubricated with ingredient No. 5.

Step 6 The lubricated granules are compressed on a suitable tabletpress.

Parenteral Formulation

A pharmaceutical composition for parenteral administration is preparedby dissolving an appropriate amount of a compound of formula I inpolyethylene glycol with heating. This solution is then diluted withwater for injections Ph Eur. (to 100 ml). The solution is then steriledby filtration through a 0.22 micron membrane filter and sealed insterile containers.

What is claimed is:
 1. A method of treatment of diseases caused by anexcess of endothelin comprising administering to a subject in needthereof, an effective amount of an endothelin receptor antagonist ofFormula (I):

E is O, S or NR_(15;) P is tetrazol-5-yl, CO₂R₆ or C(O)NR₆)S(O)_(q)R₁₀;R^(a) is independently hydrogen or C₁₋₆alkyl; R₁ is independentlyhydrogen, Ar, C₁₋₆alkyl, or C₁₋₆ alkoxy; R₂ is Ar, C₁₋₈alkyl, C(O)R₁₄ or

R₃ and R₅ are independently R₁₃OH, C₁₋₈alkoxy, S(O)_(q)R₁₁, N(R₆)₂, NO₂,Br, F, I, Cl, CF₃, NHCOR₆, R₁₃CO₂R₇, —X—R₉—Y, —X(C(R₆)₂)OR₆,—(CH₂)_(m)X′R₉ or —X(CH₂)_(n)R₉ wherein each methylene group within—X(CH₂)_(n)R₉ may be unsubstituted or substituted by one or two—(CH₂)_(n)Ar groups; R₄ is independently R_(11,) OH, C₁₅alkoxy,S(O)_(q)R₁₁, N(R₆)₂, Br, F, I, Cl or NHCOR₆, wherein the C₁₋₅alkoxy maybe unsubstituted or substituted by OH, methoxy or halogen; R₆ isindependently hydrogen or C₁₋₈alkyl; R₇ is independently hydrogen,C₁₋₁₀alkyl, C₂₋₁₀alkenyl or C₂₋₈alkynyl, all of which may beunsubstituted or substituted by one or more OH, N(R₆)₂, CO₂R₁₂, halogenor XC₁₋₁₀alkyl; or R₇ is (CH₂)_(n)Ar; R₈ is independently R_(11,) CO₂R₇,CO₂C(R₁₁)₂O(CO)XR₇, PO₃(R₇)₂, SO₂NR₇R₁₁, NR₇SO₂R₁₁, CONR₇SO₂R₁₁, SO₃R₇,SO₂R₇, P(O)(OR₇)R₇, CN, CO₂(CH₂)_(m)C(O)NR₆)2, C(R₁₁)₂N(R₇)₂,C(O)N(R₆)₂, NR₇C(O)NR₇SO₂R_(11,) OR₆, or tetrazole which isunsubstituted or substituted by C₁₋₆alkyl; R₉ is independently a bond,C₁₋₁₀alkylene, C₁₋₁₀alkenylene, C₁₋₁₀alkylidene, C₁₋₁₀alkynylene, all ofwhich may be linear or branched, or phenylene, all of which may beunsubstituted or substituted by one of more OH, N(R₆)₂, COOH or halogen;R₁₀ is independently C₁₋₁₀alkyl, N(R₆)₂ or Ar; R₁₁ is independentlyhydrogen, Ar, C₁₋₈alkyl, C₂₋₈alkenyl, C₂₋₈alkynyl, all of which may beunsubstituted or substituted by one or more OH, CH₂OH, N(R₆)₂ orhalogen; R₁₂ is independently hydrogen, C₁₋₆alkyl, C₂₋₆alkenyl orC₂₋₇alkynyl; R₁₃ is independently divalent Ar, C₁₋₁₀alkylene,C₁₋₁₀alkylidene, C₂₋₁₀alkenylene, all of which may be unsubstituted orsubstituted by one or more OH, CH₂OH, N(R₆)₂ or halogen; R₁₄ isindependently hydrogen, C₁₋₁₀alkyl, XC₁₋₁₀alkyl, Ar or XAr; R₁₅ isindependently hydrogen, Ar, C₁₋₆alkyl, or XAr; R₁₆ is independentlyC₁₋₆alkyl or phenyl substituted by one or more C₁₋₆alkyl, OH,C₁₋₅alkoxy, S(O)_(q)R₆, N(R₆)₂, Br, F, I, Cl, CF₃ or NHCOR₆; X isindependently (CH₂)_(n), O, NR₆ or S(O)_(q); X′ is independently O, NR₆or S(O)_(q); Y is independently CH₃ or X(CH₂)_(n)Ar; Ar is:

naphthyl, indolyl, pyridyl, thienyl, oxazolidinyl, thiazolyl,isothiazolyl, pyrazolyl, triazolyl, tetrazolyl, imidazolyl,imidazolidinyl, thiazolidinyl, isoxazolyl, oxadiazolyl, thiadiazolyl,morpholinyl, piperidinyl, piperazinyl, pyrrolyl, or pyrimidyl; all ofwhich may be unsubstituted or substituted by one or more Z₁ or Z₂groups; A is independently C═O, or (CR₆)2)_(m); B is independently —CH₂—or —O—; Z₁ and Z₂ are independently hydrogen, XR₆, C₁₋₈alkyl,(CH₂)_(q)CO₂R₆, C(O)N(R₆)₂, CN, (CH₂)_(n)OH, NO₂, F, Cl, Br, 1, N(R₆)₂,NHC(O)R₆, O(CH₂)_(m)C(O)NR_(a)SO₂R_(1 6,) (CH₂)_(m)OC(O)NR_(a)SO₂R₁₆,O(CH₂)_(m)NR_(a)C(O)NR_(a)SO₂R₁₆ or tetrazolyl which may be substitutedor unsubstituted by one or two C₁₋₆alkyl, CF₃ or C(O)R₆; m isindependently 1 to 3; n is independently 0 to 6; q is independently 0, 1or 2; provided R₃, R₄ and R₅ are not O—O(CH₂)_(n)Ar or O—OR₆; or apharmaceutically acceptable salt thereof.
 2. A method according to claim1 wherein P is CO₂R₆; R₁ is hydrogen; R₂ is Ar, cyclohexyl or C₁₋₄alkyl;R₃ and R₅ are independently hydrogen, CO₂R₆, OH, C₁₋₈alkoxy, C₁₋₈alkyl,N(R₆)₂, NO₂, Br, F, Cl, I, R₁₃CO₂R₇, X(CH₂)_(n)R₈, (CH₂)_(m)XR₈, orX(CR₆)2)_(m)OR₆; R₄ is hydrogen, OH, C₁ ₅alkoxy, N(R₆)₂, Br, F, Cl, I,NHCOCH₃, or S(O)_(q)C₁₋₅alkyl wherein the C₁₋₅alkyl may be unsubstitutedor substituted by OH, methoxy or halogen; R₆ is hydrogen, methyl orethyl; R₇ is hydrogen, C₁₋₁₀alkyl, C₂₋₁₀alkenyl or C₂₋₈alkynyl, all ofwhich may be unsubstituted or substituted by one or more OH, N(R₆)₂,CO₂R₁₂, halogen, or R₇ is (CH₂)_(n)Ar wherein n is zero or 1 and Ar issubstituted phenyl; R₁₁ is hydrogen, phenyl, pyridyl all of which may besubstituted or unsubstituted by one or two C₁₋₄alkyl groups; C₁₋₈alkyl,C₂₋₈alkenyl, C₂₋₈alkynyl, all of which may be substituted orunsubstituted by one or more OH, CH₂OH, N(R₆)₂, or halogen; R₁₂ ishydrogen or C₁₋₆alkyl; R₁₃ is phenyl, pyridyl, or C₂₋₁₀alkylene, all ofwhich may be unsubstituted or substituted by one or more CO₂R₆, OH,CH₂OH, N(R₆)₂, or halogen; and R₁₅ is hydrogen or C₁₋₆alkyl.
 3. A methodaccording to claim 2 wherein P is CO₂H; R₁ is hydrogen; R₂ is a group Arwherein Ar is a group (a) or (b) and in said group (a) or (b), Z₁ and Z₂are independently hydrogen, CO₂R₆, (CH₂)_(n)OH, C₁ ₄alkyl or C₁₋₆ alkoxyand A is CH₂, and one or both Bs are O; R₃ is Br, Cl, C₁₋₈alkoxy orX(CH₂)_(n)R₈, wherein X is O, n is 0, 1, or 2, and R₈ is selected from:CO₂H, OH, tetrazolyl optionally substituted by C₁₋₈alkyl; CONR₇SO₂R₁₁wherein R₇ is H or C₁₋₈alkyl, R₁₁ is C₁₋₈alkyl or phenyl optionallysubstituted by Br, Cl, F, C₁₋₈alkyl; or R₈ is phenyl or pyridylsubstituted by one or more Br, Cl, CO₂H, CH₂OH; R₅ is methoxy or N(R₆)₂wherein R₆ is H or methyl; R₄ is hydrogen; R₆ is hydrogen, methyl orethyl; R₇ is hydrogen, C₁₋₁₀alkyl, C₂₋₁₀alkenyl or C₂₋₈alkynyl, all ofwhich may be unsubstituted or substituted by one or more OH, N(R₆)₂,CO₂R₁₂, halogen, or R₇ is (CH₂)_(n)Ar wherein R₇ is (CH₂)_(n)Ar and n iszero or 1 and Ar is phenyl substituted by halogen or C₁₋₅ alkoxy; R₁₁ ishydrogen, phenyl, pyridyl wherein the phenyl or pyridyl be substitutedor unsubstituted by one or two C₁₋₄alkyl groups; C₁₋₈alkyl, C₂₋₈alkenyl,C₂₋₈alkynyl, all of which may be substituted or unsubstituted by one ormore OH, CH₂OH, N(R₆)₂, or halogen; R₁₂ is hydrogen or C₁₋₆alkyl; R₁₃ isphenyl, pyridyl, or C₂₋₁₀alkylene, all of which may be unsubstituted orsubstituted by one or more CO₂R₆, OH, CH₂OH, N(R₆)₂, or halogen; and R₁₅is hydrogen, ethyl, isopropyl, n-butyl, cyclopropylmethyl orcyclopropylethyl.
 4. A method of treatment of unstable angina, coronaryvasospasm and myocardial salvage which comprises administering to asubject in need thereof, an effective amount of a compound of Formula Iof claim
 1. 5. A method of preventing or treating restenosis whichcomprises administering to a subject in need thereof, an effectiveamount of a compound of Formula I of claim
 1. 6. A method of treatmentof pulmonary hypertension which comprises administering to a subject inneed thereof, an effective amount of a compound of Formula I of claim 1.7. A method of treatment of stroke or subarachnoid hemorrhage whichcomprises administering to a subject in need thereof, an effectiveamount of a compound of Formula I of claim
 1. 8. A compound which is(E)-3-[1-n-Butyl-5-[2-(2-carboxyphenyl)methoxy-4-methoxyphenyl]-1H-imidazol-4-yl]-2-[(2-methoxy-4,5-methylenedioxy)phenylmethyl]-prop-2-enoicacid.